Between 60million years ago and 10million years ago, the Somali Plate began rifting from the African Plate along the East African Rift.[2] Since the continent of Africa consists of crust from both the African and the Somali plates, some literature refers to the African Plate as the Nubian Plate to distinguish it from the continent as a whole.[3]
The Saharan Metacraton has been tentatively identified as the remains of a craton that has become detached from the subcontinental lithospheric mantle, but alternatively may consist of a collection of unrelated crustal fragments swept together during the Pan-African orogeny.
In some areas, the cratons are covered by sedimentary basins, such as the Tindouf Basin, Taoudeni Basin and Congo Basin, where the underlying archaic crust is overlaid by more recent Neoproterozoic sediments. The plate includes shear zones such as the Central African Shear Zone (CASZ) where, in the past, two sections of the crust were moving in opposite directions, and rifts such as the Anza Trough where the crust was pulled apart, and the resulting depression filled with more modern sediment.
Modern movements
The African Plate is rifting in the eastern interior of the African continent along the East African Rift. This rift zone separates the African Plate to the west from the Somali Plate to the east. One hypothesis proposes the existence of a mantle plume beneath the Afar region, whereas an opposing hypothesis asserts that the rifting is merely a zone of maximum weakness where the African Plate is deforming as plates to its east are moving rapidly northward.
The African Plate's speed is estimated at around 2.15cm (0.85in) per year.[4] It has been moving over the past 100 million years or so in a general northeast direction. This is drawing it closer to the Eurasian Plate, causing subduction where oceanic crust is converging with continental crust (e.g. portions of the central and eastern Mediterranean). In the western Mediterranean, the relative motions of the Eurasian and African plates produce a combination of lateral and compressive forces, concentrated in a zone known as the Azores–Gibraltar Fault Zone. Along its northeast margin, the African Plate is bounded by the Red Sea Rift where the Arabian Plate is moving away from the African Plate.
Duncan, R.A. (1984). "Age progressive volcanism in the New England Seamounts and the opening of the central Atlantic Ocean". Journal of Geophysical Research: Solid Earth. 89 (B12): 9980–90. Bibcode:1984JGR....89.9980D. doi:10.1029/jb089ib12p09980.
This article uses material from the Wikipedia article Nubian_Plate, and is written by contributors.
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